Mobile Body

The present invention relates to a mobile body.

A mobile device includes movement means for moving this device along a surface of a structure, imaging means installed on a bottom surface of this device, for imaging the surface of the structure, and determining means for comparing image data outputted from the imaging means with reference data that has been registered of each position and thereby determining a position of this device (see PATENT LITERATURE #1, for example).

PATENT LITERATURE #1: Japan Patent Application Publication No. 2019-185465.

However, in the aforementioned mobile device, due to an own weight of the mobile device, the mobile device deforms along a shape of a floor surface and thereby a distance from the floor surface (structure surface) to the bottom surface of the mobile device changes, and if the floor surface (structure surface) becomes out of a depth of field of the imaging means, then a photograph image gets blur and a current position of the mobile device may not be correctly determined.

The present invention has been conceived in view of the aforementioned problem, and it is an object of the present invention to obtain a mobile body of which a current position is correctly determined.

A mobile body according to the present invention includes a driving device that generates a driving force for running; a scanner that optically scans a floor surface and generates a first floor surface image; a controller that controls the driving device in order to reduce an error between a current position of this mobile body detected on the basis of the first floor surface image and a predetermined route such that this mobile body runs on the route; a frame body with a frame structure; and a caster that includes a driven wheel that contacts with the floor surface. The scanner (a) is arranged on a bottom surface side of this mobile body facing the floor surface, and (b) repeatedly generates as the first floor surface image a line image with a predetermined width that perpendicular to a moving direction of this mobile body; and

Further, the caster and the scanner are fixed to the frame body.

By means of the present invention, obtained is a mobile body of which a current position is correctly determined.

These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description along with the accompanied drawings.

Hereinafter, embodiments according to aspects of the present invention will be explained with reference to a drawing.

1 FIG. 2 FIG. 1 FIG. shows a perspective-view diagram that indicates a mobile body according to an embodiment of the present invention.shows a perspective-view diagram that indicates a mechanical configuration of the mobile body shown in.

1 1 11 12 12 13 11 12 12 1 FIG. 2 FIG. a b a b A mobile bodyshown inis a self-running mobile body, an AGV (Automatic Guided Vehicle), an AMR (Autonomous Mobile Robot), or the like. As shown in, this mobile bodyincludes four castersarranged at four corners of its bottom surface, scanners,, and a frame bodyto which the castersand the scanners,are fixed.

11 13 The casterincludes a driven wheel that contacts with a floor surface, and is fixed to the frame bodyso as to be rotatable.

12 12 1 12 12 1 a a b b The scanneroptically scans the floor surface and thereby generates a first floor surface image. The scanneris arranged in a front end part of this mobile bodyin the moving direction. The scanneroptically scans the floor surface and thereby generates a second floor surface image. The scanneris arranged in a rear end part of this mobile bodyin its moving direction.

12 12 1 1 a b Each of the scanners,(a) is arranged on a bottom surface side of this mobile bodyfacing the floor surface, and (b) repeatedly generates as the first or second floor surface image a line image with a predetermined width that perpendicular to a moving direction of this mobile body.

12 12 a b The scanners,scan the floor surface with a predetermined high resolution (e.g. 600 dpi).

13 13 11 12 12 13 2 FIG. a b The frame bodyis a body with a frame structure. For example, the frame bodyis obtained by pressing a metal pipe such as steel pipe into a shape. For example, as shown in, the castersand the scanners,are fixed on a bottom surface of the frame body.

1 21 21 21 21 a b c d Further, this mobile bodyincludes driving wheel units,,,.

21 21 21 21 31 32 31 33 32 34 33 13 13 13 35 33 13 13 13 a b c d a b a b Each of the driving wheel units,,,includes a driving wheelthat contacts with the floor surface, a supporting unitthat supports the driving wheelso as to be rotatable, a wheel frame unitfixed to the supporting unit, a rotatable supporting unitthat fixes an end of the wheel frame unitto the frame body(one of beams,) so as to be rotatable, and a spring memberthat provides a force to the other end of the wheel frame unittoward the frame body(the other of the beams,).

35 31 Consequently, by a restoring force of the spring member, the driving wheelis pushed to the floor surface with a predetermined pressure.

21 21 21 21 31 21 21 21 21 31 31 a b c d a b c d Further, each of the driving wheel units,,,includes a driving device (not shown) that generates and transmits a driving force for running to the driving wheel. The driving devices are individually arranged to the driving wheel units,,,, respectively, and individually generate and transmit driving forces to the driving wheels. Here, the driving device generates the driving force using a motor, and transmits the driving force to the driving wheelusing a gear or the like.

31 For example, the driving wheelincludes a driving shaft that connects to the driving device, a rigid wheel fixed to the driving shaft, and an elastic tire fitted around outside of the wheel.

3 FIG. shows a diagram that indicates a configuration of a scanner in the mobile body according to Embodiment 1.

3 FIG. 12 12 41 42 41 a b In Embodiment 1, as shown in, for example, each of the scanners,includes a light emitting unit (not shown) that emits light to the floor surface, an image sensor, a shrinking optical system(single or plural lenses) that converges to the image sensorreflection light obtained by reflection of light from the light emitting unit on the floor surface.

4 FIG. 1 FIG. 4 FIG. 1 51 52 53 54 shows a perspective-view diagram that indicates an electronic configuration of the mobile body shown in. As shown in, the mobile bodyincludes not only the aforementioned driving devicesbut a power supply device, a communication device, and a controller.

52 51 53 54 52 The power supply deviceincludes a secondary battery, for example, and supplies electric power to the driving devices, the communication device, and the controller. The power supply devicemay include a charging circuit that is connected to a commercial power supply and charges the secondary battery. Further, the secondary battery may be detachable.

53 The communication deviceperforms data communication with an external device (server or the like) with wireless communication in accordance with a predetermined protocol.

54 51 53 The controllerincludes a computer and/or an ASIC (Application Specific Integrated Circuit), and performs a data process, control of the driving devices, control of the communication device, and the like using the computer (software processing) and/or the ASIC (hardware processing).

54 51 1 1 54 1 1 The controllercontrols the driving devicesin order to reduce an error between a current position of this mobile bodydetected on the basis of the aforementioned first floor surface image (here, on the basis of the aforementioned first and second floor surface images) and a route such that this mobile bodyruns on the route. Further, the controllerstops this mobile bodyat a predetermined position (an end of the route or an intermediate point) on the basis of the current position of this mobile bodydetected on the basis of the first floor surface image.

54 1 111 101 111 54 111 51 5 FIG. 5 FIG. a In Embodiment 1, the controllerdetects the error between the current position of this mobile bodyand the route on the basis of the first floor surface image.shows a diagram that indicates an example of a floor surface. As shown in, for example, installed are a linear marker(tape or the like) that indicates the route on the floor surfaceand a markerthat indicates a stop position. Further, the controllerdetects an edge of an image of the markerin the first floor surface image, derives an error from the route in a perpendicular direction to the moving direction on the basis of a position of the edge in the first floor surface image and derives a slope of the moving direction to the route on the basis of the slope of the edge, and controls the driving devicesso as to reduce the error and the slope.

31 21 21 31 21 21 1 31 21 21 31 21 21 1 51 21 21 21 21 a b c d a b c d a b c d If a rotation speed of the driving wheelsof the driving wheel units,and a rotation speed of the driving wheelsof the driving wheel units,are set to be equal to each other, then the mobile bodyruns straight; and if a rotation speed of the driving wheelsof the driving wheel units,and a rotation speed of the driving wheelsof the driving wheel units,are set to be different from each other, then the mobile bodyturns. Therefore, so as to reduce the aforementioned error and slope, the driving deviceof each of the driving wheel units,,,is controlled.

Further, the slope of the moving direction to the route may be derived on the basis of both the error obtained from the first floor surface image and the error obtained from the second floor surface image.

54 111 54 51 1 a Furthermore, when the controllerdetects an image of the markerin the first floor surface image using pattern matching or the like, the controllercontrols the driving devicesand thereby stops the mobile body.

1 1 In the following part, a behavior of the mobile bodyaccording to Embodimentis explained.

1 54 53 54 51 1 In the mobile body, when the controllerdetects a user operation to an unshown input device (switch or the like) or receives a starting instruction using the communication device, the controllercontrols the driving devicesand thereby starts running of the mobile body.

12 12 54 1 51 1 a b Subsequently, the scanner(and the scanner) repeatedly generates as the first floor surface image (and the second floor surface image) a line image, and the controllerdetermines an error of a current position of the mobile bodyfrom a route on the basis of the first floor surface image (and the second floor surface image), and controls the driving devicesso as to reduce the error and continues running of the mobile body.

54 1 54 51 1 Further, if the controllerdetermines that the current position of the mobile bodyis a stop position on the basis of the first floor surface image (and the second floor surface image), then the controllerstops the driving devicesand thereby stops the mobile body.

12 1 101 1 54 51 1 1 11 12 13 a a As mentioned, in the aforementioned Embodiment 1, the scanner(a) is arranged on a bottom surface side of this mobile bodyfacing the floor surface, and (b) repeatedly generates as the first floor surface image a line image with a predetermined width that perpendicular to a moving direction of this mobile body; and the controllercontrols the driving devicesin order to reduce an error between a current position of this mobile bodydetected on the basis of the first floor surface image and a predetermined route such that this mobile bodyruns on the route. Further, the casterthat includes a driven wheel that contacts with the floor surface, and the scannerare fixed to the frame body.

11 12 13 11 12 12 1 1 a a a Consequently, the casterand the scannerare fixed to the highly rigid frame body, and a distance from a floor surface that the castercontacts with to the scannerhardly changes, and therefore, the floor surface tends not to become out of a depth of field of the scannerand a floor surface image under the mobile bodyis favorably obtained with a high resolution, and consequently, the mobile bodycan be correctly stopped at a desired position.

6 FIG. 6 FIG. 12 12 12 12 41 42 a a a a. shows a diagram that indicates a configuration of a scanner in the mobile body according to Embodiment 2. In Embodiment 2, the scannerorincludes a contact image sensor, as shown in, for example. Therefore, in Embodiment 2, the scanneroris a scanner of an equal magnification optical system that includes a line sensorthat includes plural photodetector elements, and a lens array

Other parts of the configuration and behaviors of the mobile body according to Embodiment 2 are identical or similar to those in Embodiment 1, and therefore not explained here.

54 53 1 54 51 1 51 In Embodiment 3, in accordance with a request from the controller, the communication device(a) transmits the first floor surface image (image data) to a predetermined server, and receives either the error between the current position of this mobile bodyand the route or a control amount corresponding to the error, that is detected by the server on the basis of the first floor surface image. Further, the controllercontrols the driving devicessuch that this mobile bodyruns on the aforementioned route on the basis of the error or the control amount (control amount for each driving device).

1 1 1 1 1 In Embodiment 3, the server maintains a floor surface image of a whole area of the floor surface (i.e. a movement area of the mobile body), determines a position of the first floor surface image (i.e. a partial floor surface image transmitted and received from the mobile body) in the floor surface image using pattern matching or the like, and determines an actual current position corresponding to this position. Further, the server maintains route information of the mobile body, and determines an error between a route based on the route information and the current position, and transmits either the error or the corresponding control amount to the mobile body. Here, line images of a predetermined number of lines are transmitted as the first floor surface image to the server.

1 1 53 54 51 1 Further, if the derived current position agrees with a preset stop position, then the server transmits a stopping instruction to the mobile body, and in the mobile body, if the stopping instruction is received by the communication device, the controllerstops the driving devicesand thereby stops the mobile body.

7 FIG. 101 112 1 shows a diagram that indicates another example of a floor surface. For example, the floor surfacehas not only an original pattern(i.e. surface pattern of floor material such as tile or concrete) but a scratch, a stain or the like, and therefore, in the high resolution surface image, image patterns at different positions are different. Therefore, on the basis of the first floor surface image, a current position of the mobile bodycan be determined.

Here, although the first floor surface image is transmitted to the server, the first and second floor surface images may be transmitted to the server as well, and current positions may be derived of the respective first and second floor surface images as well.

1 Further, the first floor surface image (and the second floor surface image) may be transmitted after compressing them in the mobile body, and may be decompressed in the server.

1 1 Furthermore, without using the aforementioned server, the mobile bodymay maintain a floor surface image of a whole area of the floor surface (i.e. a movement area of the mobile body), determine a position of the first floor surface image in the floor surface image, and determine an actual current position corresponding to this position.

Other parts of the configuration and behaviors of the mobile body according to Embodiment 3 are identical or similar to those in Embodiment 1 or 2, and therefore not explained here.

8 FIG. 8 FIG. 1 1 11 12 81 82 81 82 1 81 54 1 a a a shows a side-view diagram that indicates a mobile body according to Embodiment 4. In Embodiment 4, the mobile bodyincludes a housingthat protrudes over the casterand the scannerin a frontward direction, an infrared sensorfor collision prevention, and a main switch. The infrared sensorand the main switchare arranged in a front end of a frontward side of the housingas shown in, for example. If an obstacle or the like is detected by the infrared sensor, the controllermakes an emergency stop of this mobile body.

8 FIG. 1 12 12 a a a As shown in, for example, since the housingprotrudes over the scannerin the frontward direction, environmental light tends not to enter the scanner.

Other parts of the configuration and behaviors of the mobile body according to Embodiment 4 are identical or similar to those in any of Embodiments 1 to 3, and therefore not explained here.

Further, it should be understood that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

12 b For example, in the aforementioned embodiment, the scannermay not be installed.

For example, the present invention is applicable to a mobile body.